Car coupler



April 23, 1963 w. J. METZGER CAR COUPLER 2 Sheets-Sheet 1 Filed Oct. 11, 1960 INVENTOR. WILLIAM J. METZGER ATTORNEY W. J. METZGER April 23, 196 3 CAR COUPLER 2 Sheets-Sheet 2 Filed 001;. 11, 1960 INVENTOR WILLIAM J METZGER ATTORNEY Travel along Guiolaway by Lock 334336662 CAR COUPLER William 3. Metzger, East Cleveland, Clhio, assignor to National Castings Company, a corporation of 02120 Ffled st. 11, 1969, Ser. No. 61,365 3 Qiaims. (Cl. 213100) This invention relates to fixed-jaw automatic couplers of the type, e.g., the Willison coupler, in which a lock is slidably supported on a guideway inclined upwardly and rearwardly from a front coupler-engaging face whereby the lock may be propelled by gravity forwardly to its locking position. Such a coupler ordinarily includes a rotor for forcibly transferring the lock rearwardly along an ambit defined by the guideway. Such a rotor is characterized in the conventional type of Willison coupler, as well as the coupler of this invention, by a radial arm in cam-relation with a cam-following surface of the lock ordinarily defined by the periphery of a recess therein.

This invention, while beneficial generally in the use of fixed-jaw type couplers, originates primarily in attempts to use a conventional type of Willison coupler on railway cars equipped with side buffers. Considerable difiiculty has been encountered in uncoupling cars coupled under a condition of tension, e.g., when standing on a curved track. In this situation, couplers must be uncoupled while subjected to tension imposed thereon by the compressed opposed side buffers located inwardly of the track curve relative to the couplers. The friction to which the lock is subjected with respect to the guideway of the head and the trapped lock of an opposing coupler is approximately proportional to the tension acting on the couplers. In at least one instance, it has been specified that coupled couplers under 4,000 pounds tension be uncoupleable by the mechanism of one of the couplers at a manual effort of approximately 75 pounds applied to a conventional operating rod, such as that ordinarily carried on the end of a car. In uncoupling conventional fixed-jaw couplers under 4,000 pounds tension, it has been found necessary for an operator to apply 250 to 300 pounds of force on the handle of an operating rod to retract the lock.

A principal object of this invention is to provide a fixed-jaw or Willison-type coupler which may be uncoupled under all reasonably anticipated uncoupling conditions at less .than 100 pounds of manual effort applied to an operating rod.

The present invention is embodied in a coupler cornprising a head having collateral relatively-fixed jaws and a sloping guideway defined by upwardly and rearwardly inclined rectilinear interior surfaces; a lock reciprocably confined in the guideway and movable therealong by gravity forwardly into a locking position; a rotary lock lifter mounted on the coupler head along an axis of rotation in transverse horizontal relation to the coupler length; the lock lifter having a radial arm in cam relation with a cam-following surface defined by the lock for forcibly transferring the lock rearwardly along the guideway.

The present invention resides essentially in respective contours of the radial arm and the cam-following surface which enable the lock and lifter to engage at the beginning of an unlocking operation along a path of contact canted upwardly and rearwardly more steeply than the guideway and resulting in a lifting action on the lock and, hence, a reduction of friction by the lock with the guideway. That is to say, when the lock in its locking position commences the unlocking stroke, the radial arm of the lifter engages the cam-following surface along a common tangent of which the line or direction of force exerted by the lifter on the lock is perpendicular thereto BfidfifihZ Patented Apr. 23, 1963 and extends rearwardly and upwardly at steeper inclination than the guideway. This arrangement results in a force tending to lift the lock, and when exerted on a rear lock portion, as in a preferred embodiment, tends to rotate the lock in a vertically longitudinal plane of the coupler within the guideway about a forward area of the lock engaged with the lock of an opposing coupler.

A further important feature of the invention is the unusually short lever length applied by the rotor to the lock at its locking position. The lever advantage thus achieved results in a reduction of torque applied through the operating rod necessary for lock movement. The shorter lever length of the rotor utilized at the beginning of the unlocking stroke enables the use of a shorter lever length throughout a critical initial stage of lock retraction than is available in the known fixed-jaw coupler constructions.

In the drawing with respect to which invention is described in detail:

FiGS. 1 to 6 are fragmentary elevations in longitudinal section illustrating the coupler in a series of stages depicting movement of a lock and lock lifting rotor from a locking position (FIG. 1) to an unlocking position (H6. 6).

FIG. 7 is an elevation of the rotor shown partly in FIGS. 1 to 6 as viewed transversely to its axis of rotation.

FIG. 8 is an elevation of the rotor of FIG. 7 as viewed in the lengthwise direction of its axis.

FIG. 9 is a fragmentary elevation in longitudinal section of the head of the coupler shown in FIGS. 1 to 6 illustrating the paths of contact between (1) the lock and rotor of a prior art coupler, and (2) the lock and rotor of a coupler in accordance with this invention.

FIG. 10 is a fragmentary enlargement of the improved coupler as illustrated in FIG. 1.

FIG. 11 is a fragmentary enlargement of a prior art coupler as illustrated partly in dotted line in FIG. 1.

FIG. 12 is a graph based on the curves of rotor and lock engagement appearing in FIG. 9 depicting the change in lever length at the point of engagement of the rotor with the lock occurring (1) during lock retracting strokes in the improved coupler of this invention, and (2) in a prior art coupler.

FIG. 13 is a fragmentary plan view of the head portion of the fully assembled coupler of FIGS. 1 to 9.

The drawing illustrates a coupler comprising a head 6, a lock 7, and a rotary lock-lifter rotor 8. The rotor comprises a pin 10 supported concentrically by the head along an axis 11 extending horizontally transversely of the coupler length. The head 6 comprises bearings at each side of the rotor for receiving journal portions of the pin 10. Hence, the rotor is rotatable with respect to axis 11 in fixed relation with the head.

The head 6 has a guideway 12 defined by interior surfaces of the head, such as surface 15 defining the floor or lower extremity and surface 16 defining the ceiling or upper surface of the guideway. Other interior surfaces of the head disposed along opposite sides of the lock 7 join the surfaces 15 and 16 in outlining the guideway. Surfaces 15 and 16 are rectilinear and generally parallel in an upward and rearward direction with respect to the forward coupler-engaging face 18 of the coupler and thereby determine the direction of ambit for movement for the lock from its forward locking position to its rearward unlocking position.

The length of the ambit of the lock 7 is determined by the rearward extent of a slot 19' which receives the rotor shaft or pin 10 and the inner surface 25 of the rear head wall. Locking position terminating forward movement of the lock is established by an engagement of the pin 10 with the rearward end surface 21 of the slot. The pin 10 and the surface 21 are shown engaged in FIG. 1 and separatcd, e.g., in FIGS. and 6. A hub portion 22 of the rotor is cut out adjacent the pin '10 to accommodate a lock portion defining the surface 21 to permit the relationship shown in FIG. 1.

The position of the lock shown wherein the lock has passed rearwardly to the forwardmost point at which it will release a jaw of an opposing coupler trapped by the coupler is shown in FIG. 6. However, the lock has freedom to move rearwardly of this position until its rearward-facing surface engages the rear wall surface 25.

The rotor 8, when viewed in the rear to front direction of the coupler (see FIG. 7) takes a U-shaped contour of which the left portion 28 is that shown in FIGS. 1 to 6. The rotor comprises a radial arm 29 extending into a recess 31 of the lock. The right portion of the rotor shown in FIG. 7 extends upwardly along the exterior side of a depending rib portion 30 of the head. The right portion 32 comprises an eye section 32a, as shown in FIG. 8, adapted for connection with a pull rod or chain not shown.

' Considering now the essential features of the invention which reside in the contours of the rotor arm 29 and the lock recess 31, as they occur within a vertical longitudinal plane of the coupler, FIGS. 1 to 6 and illustrate in full line the contour of the improved coupler and, in dot-anddash line, the contour of the prior art construction considered closest to that of the invention. For clarity, FIG. 11 presents the prior art construction in full line with lock 7P in locking position. The letter P is added to certain numerals relating to the present invention to indicate comparable prior art structures herein.

With attention to the invention as represented by the full lines of FIGS. 1 and 10, the arm 29 has an S-shaped peripheral surface 33 comprising a concave section 34 connecting approximately tangentially with the peripheral surface of the hub portion 22, and a convex section 35 of greater length and radius of curvature than the concave section.

At the forwardmost locking position shown in FIG. 1, the surface 33 and body of the arm 29 are disposed in a generally forward relation with respect to the hub portion 22 and axis of the rotor. In moving the lock rearwardly out of locking position through the various stages progressively represented by FIGS. 1 to 6, the peripheral surface 33 of the arm functioning as a cam engages progressive sections of a rearward cam following surface 38 .partly defining the recess 31. Surface 38 faces downwardly and forwardly and terminates at its lower end in a convex shoulder 39. The recess and the arm are purposely contoured to dispose the shoulder 39 in contact with the surface 33 along the concave area 34- and as close to the hub 22 as the contours will permit at locking position of the lock. Contact of the shoulder with the concave area occursas shown in FIG. 10 along a tangent 41 of both surfaces. The surfaces are contoured for rolling contact and hence the force exerted by the arm on the lock at this instant occurs along a perpendicular to the tangent 41 represented by a dot-and-dash arrow 42. Important to note is that this arrow is more steeply inclined than, and extends at an angle relative to, the parallel surfaces and 16 which define the direction of movement of the lock 7.

On the other hand, the prior art construction shown in FIGS. 1 and 11 involves initial contact of the prior art rotor arm SP and the prior art recess surface 38P at a point of tangency 44. The tangent represented by line 45 passing through this point is approximately perpendicular to the surfaces 15 and 16 which are in turn parallel to the direction of movement of the lock. In the prior art coupler, the lock 7P is hence urged in a direction perpendicular to the tangent 45 and parallel to its path of movement along a dot-and-dash arrow 46. It is actually found that the combination of forces acting on the lock 7P of the way surfaces.

4i prior art construction is such as to increase the pressure of the lock, particularly along the rearward portion of its undersurface, on the guideway surface 15.

In the coupler of this invention, any force incidental to uncoupling tending to increase the pressure of the lock on the bottom guideway surface is overcome and in fact iover-balanced to such an extent as to initially swing the rearward portion of the lock upwardly. Such upward swinging occurs as the lock rotates or tends to rotate about a forward lateral surface portion 48 of the lock disposed forwardly of a transverse coupling plane 49 in engagement with the entrapped lock of another coupler coupled to coupler 5. The plane 49 is defined as a vertical plane in perpendicular relation with the longitudinal coupling line or :axis along which two smilar couplers are coupled and with respect to which similar parts of the couplers [are equally spaced. The axis about which the lock 7 is tilted when its parent coupler is uncoupled from another under tension can be located in an approximate manner as extending horizontally and perpendicularly relative to the length of the coupler centrally through the area 48. Provision of a clearance 51 between an upper inclined surface 52 of the lock and the upper guide surface 16 enables a slight twisting movement of the lock 7 in a vertical plane during uncoupling. Initial twisting of the lock not only breaks it loose from the lock of an opposing coupler along its own surface 48 under high leverage condition to overcome static friction but lessens the pressure of the lock on floor surface 15. Thereafter, the lock may be moved more advantageously along the length of the guideway 12 as comparedwith the prior art construction. Its movement is facilitated by a force component tending to lift the look away from the surface 15 through a substantial initial portion of the lock ambit.

FIG. 4 depicts a stage of the coupler unlocking operation wherein the force exerted by the rotor arm of this invention on the lock is approximately parallel to the longitudinal direction of the guideway. In the following stages (FIGS. 5 and 6) the direction of force progressively inclines toward the lower surface of the guideway in a way tending to increase friction therealong. However, this does not result in any disadvantage when compared with prior art construction because of (1) the relatively short lever arm exerted by the rotor arm 29, (2) the decreasing area of the lock in contact with the lock of an opposing coupler, and (3) the kinetic energy is stored in the mechanism at this point of operation.

FIGS. 1 to 3 are particularly useful in pointing :out by reference to the arrows one of the major advantages of the invention, i.e., that the rotor arm 29 tends to initially twist and thereafter lift the lock away from the lower guideway surface 15 to substantially reduce starting friction relative to the lock of an opposed coupler and reduce the friction encountered by the lock with the lower guide- FIGS. 1 to 6 illustrate the unusually low lever length of the rotor azrm applied throughout the unlocking operation. Pointsof contact between the rotor arm and the lock are plotted graphically in FIGS. 9 and 12. to ascertain the paths of engagement in both the improved coupler in accordance with this invention and the prior art coupler. FIG. 9 illustrates curves 55 and 56 of engagement, respectively, of the improved coupler and the prior art coupler in actual relationship with the surfaces defining the guideway 12 provided by the head 6. FIG. 12 illustrates that curves 55 and 56 are plotted with respect to horizontal and vertical ordinates. FIGS. 9 and 12. point out a second major advantage of the invention, i.e., the mechanical advantage achieved through unusually short lever length of the rotor 8.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention of excluding such equivalents of the invention described or the portions thereof as fall within the purview of the claims.

What is claimed is:

1. An automatic car coupler comprising: a head having fixed collateral jaws and an internal guideway extending upwardly and rearwardly relative to a couplerengaging face of the head; a lock supported by the head for reciprocation along said guideway; a rotary locklifter supported by the head for rotation about an axis in fixed horizontal transverse relation to the coupler length and having a radial arm; said lock having a cam-following surface facing in a generally forward and downward direction in engaged cam relation with the outer peripheral surface of the arm and terminating at its lower end in a convex shoulder; said peripheral surface being generally S-shaped and extending generally outwardly from said axis; said peripheral surface comprising a smaller concave area terminating adjacent said axis for receiving said shoulder, and a larger convex area of substantially greater radius of curvature than the concave area extending radially outwardly from the concave area relative to said axis; said arm and said peripheral surface extending generally forwardly relative to said axis with said shoulder received in the concave area, at the forward lowest position of the lock; said shoulder and concave area engaging along a common tangent for exerting a propulsive force on the lock in an upward and rearward direction perpendicular to said tangent and steeper than the inclination of the guideway during initial rearward movement of the lock along the guideway; said cam following surface and said peripheral surface being relatively contoured to engage in rolling contact along a series of tangents of which the inclination of the perpendiculars thereto is gradually reduced to the inclination :of the guideway in movement of the lock from said lowest position to a rearward position for unlocking said coupler with respect to another coupler when coupled therewith.

2. The automatic car coupler of claim 1 wherein: the upper extremity of the guideway defines a vertical clearance with respect to the lock allowing a twisting movement of the lock in a vertical plane relative to the guideway preliminary to moving lengthwise of the guideway from locking position.

3. An automatic car coupler comprising: a head having fixed collateral jaws and an internal guideway extending upwardly and rearwardly relative to a coupler engaging face of the head; a lock supported by the head for reciprocation along said guideway between a rearward unlocking position and a forward locking position disposing a forward portion of the lock in a region between said jaws in juxtaposition with one jaw wherein one side of said forward portion is substantially enaged with the lock of a coupler coupled with said coupler; a rotary lock-lifter supported by the head for rotation about an axis in horizontal transverse relation to the coupler length and having a radial arm; the lock having a recess in which said arm is loosely received to provide freedom therein for toggle motion of the arm relative to the lock; said recess partly defined by a cam-following surface facing in a generally forward and downward direction in engaged cam relation with the peripheral surface of the arm, and terminating at its lower end in a convex shoulder; said peripheral surface extending generally outwardly from said axis in S-shaped contour to provide a concave area terminating adjacent said axis for receiving said shoulder, and a larger convex surface of substantially greater radius of curvature than the concave area extending radially outwardly from the concave area relative to said axis; .said arm and said peripheral surface extending, at said locking position, generally forwardly relative to said axis with said shoulder received in said concave surface in generally vertical relation therewith; said shoulder and area engaging along a common tangent of which a line of force perpendicular thereto extends in an upward and rearward direction of steeper inclination than that of the guideway; said line of force being the direction of lifting effort exerted 10H the lock by the arm; said peripheral surface and said cam-following surface being relatively contoured for progressive engagement along common tangents of which the inclination of the perpendiculars thereto is gradually reduced to the inclination of the guideway in not less than one-fourth of travel of the lock from locking position to unlocking position.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN AUTOMATIC CAR COUPLER COMPRISING: A HEAD HAVING FIXED COLLATERAL JAWS AND AN INTERNAL GUIDEWAY EXTENDING UPWARDLY AND REARWARDLY RELATIVE TO A COUPLERENGAGING FACE OF THE HEAD; A LOCK SUPPORTED BY THE HEAD FOR RECIPROCATION ALONG SAID GUIDEWAY; A ROTARY LOCKLIFTER SUPPORTED BY THE HEAD FOR ROTATION ABOUT AN AXIS IN FIXED HORIZONTAL TRANSVERSE RELATION TO THE COUPLER LENGTH AND HAVING A RADIAL ARM; SAID LOCK HAVING A CAM-FOLLOWING SURFACE FACING IN A GENERALLY FORWARD AND DOWNWARD DIRECTION IN ENGAGED CAM RELATION WITH THE OUTER PERIPHERAL SURFACE OF THE ARM AND TERMINATING AT ITS LOWER END IN A CONVEX SHOULDER; SAID PERIPHERAL SURFACE BEING GENERALLY S-SHAPED AND EXTENDING GENERALLY OUTWARDLY FROM SAID AXIS; SAID PERIPHERAL SURFACE COMPRISING A SMALLER CONCAVE AREA TERMINATING ADJACENT SAID AXIS FOR RECEIVING SAID SHOULDER, AND A LARGER CONVEX AREA OF SUBSTANTIALLY GREATER RADIUS OF CURVATURE THAN THE CONCAVE AREA EXTENDING RADIALLY OUTWARDLY FROM THE CONCAVE AREA RELATIVE TO SAID AXIS; SAID ARM AND SAID PERIPHERAL SURFACE EXTENDING GENERALLY FORWARDLY RELATIVE TO SAID AXIS WITH SAID SHOULDER RECEIVED IN THE CONCAVE AREA, AT THE FORWARD LOWEST POSITION OF THE LOCK; SAID SHOULDER AND CONCAVE AREA ENGAGING ALONG A COMMON TANGENT FOR EXERTING A PROPULSIVE FORCE ON THE LOCK IN AN UPWARD AND REARWARD DIRECTION PERPENDICULAR TO SAID TANGENT AND STEEPER THAN THE INCLINATION OF THE GUIDEWAY DURING INITIAL REARWARD MOVEMENT OF THE LOCK ALONG THE GUIDEWAY; SAID CAM FOLLOWING SURFACE AND SAID PERIPHERAL SURFACE BEING RELATIVELY CONTOURED TO ENGAGE IN ROLLING CONTACT ALONG A SERIES OF TANGENTS OF WHICH THE INCLINATION OF THE PERPENDICULAR THERETO IS GRADUALLY REDUCED TO THE INCLINATION OF THE GUIDEWAY IN MOVEMENT OF THE LOCK FROM SAID LOWEST POSITION TO A REARWARD POSITION FOR UNLOCKING SAID COUPLER WITH RESPECT TO ANOTHER COUPLER WHEN COUPLED THEREWITH. 